Not long ago, a friend mentioned to me Herman Hesse's decades old novel, Siddhartha. Loosely based on the life of Siddhartha Gautama, the Indian prince and wandering mystic who became known as the Buddha, founder (although he didn't necessarily intend to) of Buddhism, Siddartha tells the story of how its character finds enlightenment.  It describes his journey through the landscapes of his native land until one day he happens upon a river.  As he stood on the banks of the river, watching it flow and flow and flow, noticing that although it was always changing it always stayed the same, and pondering how such a thing could be, he decided that, in this tiny prism of the natural order, he was seeing the essence of existence.  He must move, but he must remain; change, but not.  He must meld into the oneness of being, the dynamic stasis of the dichotomy of presence and absence.
     Though this seems a contradiction in terms, on the other hand, it helps us understand more of what life really is.  Always here (at least for next several billions of years!), life is immutable.  Yet it is ever unwinding, its various manifestations, its plants and animals, appearing, then disappearing, only to appear, through decay and rebirth, again, in new forms.  Life is always here, but it is never expressed in the same way.
     Our challenge is therefore to manage the joy of presence with the emptiness of absence.  While we are here, we rejoice; when we see ourselves fading, we become sad (even if in the end, we accept it).  We can do this by embracing presence and absence simultaneously; by accepting each one in their place and turn; or by assenting to the possibility--and this is a powerful possibility--that beyond presence and absence, there is yet another presence to live:  the resurrection and afterlife.
     We stand before the rivers of our lives, wondering what they mean, wondering what their mix of change, sameness, presence, and absence tell us about existence.  And we always stumble before the unknown.
     And in the end, it is a question of which unknown we wish to believe:  what is there and not, or what is there and not--and, in resurrection (the universal human longing and the heart of the Christian faith) there again?